I have to admit that I'm about to ask for some serious hand holding. I'm new to planted tanks and my brain is tanked from dealing with 7th graders all week. I'm asking for what I give them all week! Yikes, I didn't think I'd sink to this level. Anyway...
I've got a 100 tank with Eco-complete substrate. It's full of plants that will work well with Discus, which I don't have yet. I'm running CO2 and 204 watts of light. I did some reading a while back and bought the following:
Via Bloom (solid)
Nutrafin Plant Gro (liquid)
The nutrafin seems like a mistake as the directions say 50 mL per week for my tank and the bottle only has 120 mL. It was also a bit expensive.
So... how much of this stuff should I add and what else should I get?
Okay, first you said you had 204 watts, we need to know what type of light it is and how far from the lights to the substrate.
I can't comment on the nutrafin or the via bloom.
Depending on the strength of the lighting/if co2 is injected/ and plant mass will determine how much you will need to dose.
There are a couple methods on how to dose. Estimative Index (EI), which is generally for highlight co2 injected systems. You can also search PPS-Pro method which might be better for your situatioin.
You will need a Micro fert such as CSM+B, Seachem Flourish or othe brand of "trace"/Micro ferts. These consist of a broad spectrum of nutrients in smaller dosages. You may have it there as nutra fin/bloom I'm not sure and I can't research because I'm running on 56k internet right now.
You also need Macro nutrients, these are nutrients that plants use in larger amounts Nitrogen via Potassium Nitrate, Phosphorus via Mono Potassium Phosphate, and Potassium via Potassium Sulfate.
You may also want to get a phosphate test kit and a Nitrate test kit if you already haven't. Many people I've talked to especially well water may contain Nitrates/Phosphates from farm fertilizer.